A major office tenant is returning to the city centre with a new six-storey building.

Accountancy firm PwC has signed on as anchor tenant for a new building on Cashel St, near the Bridge of Remembrance.

The new building is set to start construction in the next three months, with completion planned for mid-2016.

The building, designed by architecture firm Warren and Mahoney, will meet 130 per cent of the building code and have a distinctive glass facade patterned with tree shapes.

PwC regional managing partner Maurice Noone said he wanted the company to contribute to the Christchurch rebuild.

"It's important for us to play our part in rebuilding our city and moving back into the city's heart is another demonstration of our commitment to the city. We've always planned to be back,'' he said.

Canterbury Employers' Chamber of Commerce chief executive Peter Townsend said the new building was a sign that the rebuild was starting to accelerate.

"This is another step along the way,'' he said.

"We will see more of these kinds of announcements and it is all good news. Developers can see that it is practical and possible to build in the city centre on reasonable timelines now most of the demolition work is complete.''

The move comes just weeks after Vodafone announced plans to build a new office in the city centre, with more announcements expected in the next few months.

Legal firm Chapmann Tripp will also move into the building when it is completed in mid 2016. The firm will take a smaller floor in the building.

Chapmann Tripp partner, Andrew Woods said they were keen to return to the city centre.

"We are excited about returning to the heart of the city. We've remained committed to this goal since leaving the centre in 2011 and believe that the rejuvenation of the CBD is an important step in the city's recovery.''